1. Field of the Invention
The present invention relates to an antenna, and more specifically to a multi-band antenna applied on a portable electronic device.
2. The Related Art
With the constant development of the electronic technology, the wireless communication technology is well developed and progressed, too. For instance, Worldwide Interoperability for Microwave Access (WiMAX) is a wireless digital communication system, also known as IEEE802.16, that is intended for wireless “metropolitan area networks”. The WiMAX can provide Broadband Wireless Access (BWA) up to 30 miles (50 km) for the fixed stations, and 3-10 miles (5-15 km) for the mobile stations. The WiMAX, which can be used for wireless networking the same as the currently common Wireless Fidelity (WiFi) protocol, referred to as a second-generation protocol, allows for more efficient band-width use, interference avoidance, and is intended to allow high data rates over a long distance, so as to be used widely on portable electronic devices, such as notebook computers. A wireless LAN (or WLAN, for wireless local area network, sometimes referred to as LAWN, for local area wireless network) is one in which a mobile user can connect to a local area network (LAN) through a wireless (radio) connection. The WLAN has a maximum data rate of 11 Mbit/s. At present, most of the portable electronic devices are equipped with multi-band antennas which can receive and send multiple frequency bands provided by the WiMAX and the WLAN. However, the conventional multi-band antennas generally have lower efficiency of receiving and sending signals, not good enough to meet the demands of the users. Therefore, it is desirable to design a multi-band antenna having better efficiency for receiving and sending signals.